Dental handpiece.



No. 713,825. Patented Nov..|a, |902.`

J. n. wlucens.

DENTAL HANDPIECE. (Apialcatian. lad Nov. 7, 1901.)

(No Model.)

nu: Nonms Ferias co. Pnuou'ma.. wumcmN. n. c.

Darren @raras Parnnr OFFICE.

.TOI-IN D. VILKENS, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE DENTALPROTECTIVE SUPPLY COMPANY, OF CHICAGO, ILLINOIS, A CORPO- RATION OFILLINOIS.

DENTAL HANDPIECE.

SPECIFICATION forming part of Letters Patent No. 713,826, dated November18, 1902.

Application filed November 7, 1901. Serial No. 81,375. (No model.)

:To all whom t may concern.:

Be it known that I, JOHN D. VJILKENS, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Dental Handpieces,ofwhich the following is a specification.

My invention relates to certain improvements in handpieces for dentalengines of that class having a rotating hollow spindle containing asliding chuck; and it consists in certain novel features of constructionof those parts which are manipulated to clamp and release the toolcarried by the handpiece.

My invention in its preferred form is illustrated in the accompanyingdrawings, in

Figure l is a side elevational view of the handpiece complete with thetool carried thereby. Fig. 2 is a central longitudinal sectional View,partly in elevation, of the tool viewed in a plane at right angles tothat of Fig. l. Fig. 3 is a view similar to Fig. 1,

showing the rotating spindle with the outer casing removed. Fig. l is adetail elevational view of the stationary outer casing. Fig. 5 is adetail view of the outer non-rotatable slidable locking-sleeve and itspivoted locking device carried by the outer casing. Fig. 6 is atransverse section of the same on the line 6 6 of Fig. 5 looking in thedirection of the arrow. Fig. 7 is a fragmentary detail View,considerably enlarged, illustrating the means for securing in operativerelation the locking device carried by said outer lockingsleeve; andFig. S is a detail view of the rear section of the rotating spindle.

The handpiece shown in the accompanying drawings belongs to that classwherein the tool-driving spindle is revolubly mounted within anon-rotating casing or sheath, the spindle being adapted for connectionat its rear end to a flexible shaft or other means for rotating it, suchas is well known in connection with the dental engine of ordinary use.

Referring to the drawings, 9 indicates an inclosing sheath or casing,whichis provided with the usual hard-metal nose-piece lO and alongitudinal aperture 11, formed through its wall toward its rear end.

12 indicates a sheath-collet having threaded ends, the forward one ofwhich threaded ends engages with the internal threads of the rear end ofthe casing 9 and the rear of which threaded ends engages with acouplingsection. collet l2 is an internal spind1e-collet13, having ajam-nut 14.

At 15 is shown the rear section of a divided spindle, which has itsforward end externally threaded at 16 for engagement with the rear endof the front spindle-section, (shown at 17.)

The forward end of the rear spindle-section 'l5 is longitudinallyslotted centrally thereof, as shown at 18, and within the slot thusformed is contained a wedge-shaped camlever 19, pivotally suspended atits upper forward end on a pivot-pin 20, mounted in and transversely ofthe body of the spindle-section and across the upper forward end of theslot 1S. (See Figs. 2 and 3.) The upper camface of the lever 19 isserrated or formed with a series of notches, asshown at 2l, and theforward end or nose of the lever is adapted to abut the rear end of achuck-operating rod 22, which lies within and slidingly engages the rearend of the forward section 17 of the spindle. Within the same section ofthe spindle and directly in advance of the chuck-operating rod 22 islocated an axiallybored connection-piece 23, which latteris entered atits rear end by a centering-pin 22 on the forward end of thechuck-operating rod 22 and at its forward end is inwardly beveled ortapered to receive the rear end of a tubular chuck 24, which latter issplit at both ends, as shown, and receives the shank of the tool 25. Thebore of the forward end of the spindle is gradually contracted, fromwhich it will be evident that an endwise pressure exerted longitudinallyof the spindle by the lever 19,acting through the chuck-operating rod 22and the connection-piece 23, will tend to force the chuck 24E forwardlywithin the spindle, which serves as a containingsleeve therefor, in sucha lnanner as to cause the split ends of the chuck to clamp and hold thetool. Thetapered end of connectionpiece 23 also compresses and closesthe rear end of the chuck.

(Not shown.) WVithin the sheathi IOO ' swung outwardly on its pivot.

Referring now specifically to the means I prefer to employ for actuatingthe lever 19 to thus clamp and release the tool 26 designates a sleevemounted to slide frictionally over the rear portion of the outer casing9, which contains the slot 11. In an external annular rib 27, formedabout said sleeve, is pivoted at its base a locking-finger 28, whichfinger overlies the slot 11 and is provided with a depending lug 29,which passes through said slot 1l when the finger lies upon and parallelwith the wall of the sleeve and is withdrawn therefrom when the fingeris The rear end of the sleeve 26 is exteriorly screw-threaded and isengaged by an internally-threaded ring 30, and a longitudinal groove orsocket is cut through the screw-threads of the sleeve in alinement withthe finger 28, as shown at 3l, to provide a seat for an extendedprojection or nose 32, formed integral with the finger 28, which may beoverrun by the ring 30, thereby locking the finger 28 in its operativeposition, all as best shown in the detail View, Fig. 7. This sleeve 26thus constituted and equipped I have termed the outer lockingsleeve, andthe same is adapted to be slid forwardly or rearwardly of the casing ofthe handpiece without undue friction thereon.

Within the casing and slidably mounted upon the rear slotted section15of the spindle and in such a location relatively to the sleeve 26 as tolie within the latter is an in' ner locking-sleeve,(designated by 33.)This sleeve has acircumferential groove 34 formed therein atits rearend, which groove is adapted to receive the depending lug 29 when thelinger 28 is in its closed oroperative position.

A screw-threaded pin 35 screws through the wall of the sleeve 33 inadvance of the groove 34 and enters the slot 18, formed in the rearsection 15 of the spindle, the lower end of this pin engaging theserrated or notched camface of the lever 19, all as plainly shown inFig. 2. By reason of its screw-threaded engagement with the sleeve thispin may be finely adjusted to enter the slot to varying degrees of depththerein as the proper adjustment of the parts affected thereby mayrequire.

The operation of the parts thus formed and arranged may be brieydescribed as follows: With the several parts in the relative positionsshown in Fig. 2, the shank of the tool 25 has been entered and isloosely held between the jaws of the chuck in the manner usual in thisclass of tools. In order to lock the tool in the chuck, the outersliding sleeve 26 is pushed forward upon the casing, and through theengagement of the lug 29 with the groove of the inner collar 33 thelatter collaris simultaneously slid forward upon the spindle 15. Thislatter forward travel of the collar 33 of course advances the pin 35upward over the cam-face of the cam-lever 19, the lower end of the pinslipping from one notch to the next and tending by reason of itsengagement withsaid notches to hold the cam-lever locked in eachsuccessively increasingly depressed position. This depression of therearwardly-extending body portion of the cam-lever tends to thrust itsfront face forward against the rod 22, thereby advancing the latter andthe connection-piece 23, and through these connections crowding thechuck 24 hard up into the forward inwardly-tapered end of the spindle,thereby causing the chuck to grasp and clamp the tool with greatfirmness at both ends thereof. A reverse movement imparted to the sleeve26'by the operator will serve to release the tool by permitting thechuck and connectionpiece to recede slightly and the clamp-jaws thereofto expand under the natural elasticity of the :metal of which it iscomposed.

NVhen it is desired to dismantle or take the tool apart, by unscrewingthe ring 30 the iinger 28 may be released and swung outwardly,

thereby withdrawing the lug 29 and breaking the connection between theinner and outer sleeves. By then unscrewing and withdrawing the rearcollet 12 the rotary spindle and its contained parts may be withdrawnfor cleaning, oiling, adjustment, or replacement of parts, or for anyother purpose. It will be obvious that` the connection piece 23 is by nomeans an essential element of the invention, since the chuck-operatingrod 22 may be made of such a length that its forward end will directlyengage the rear end of the chuck. This connection-piece is, however, auseful adjunct of the device, for the reason that different dentaloperators prefer handpieces of varying lengths, and the use of theconnection-piece 23 enables the chucks and the chuck-operating rods tobe all made in one size and used in spindles of varying lengths by meansof connection-pieces of correspondingly varied lengths.

What I regard as an important feature of my present invention resides inthe location and arrangement of the chuck-closing devices relatively tothe spindle and its casing, whereby the chuck is clamped through aforward sliding movement of the chuck-operating devices and is releasedthrough a rear movement of said devices. In many constru ctionsheretofore employed wherein the chuck is clamped and released throughthe operation of an external sliding member mounted upon the outercasing of the handpiece-as, for instance, in my former patent, No.533,574, February 5, 1895, u-pon which this invention is animprovement-the chuck has been released by a forward movement andclamped by a rearward movement of the chuck-operating sleeve or otherdevice. The result of this has often been that the chuck has beenreleased accidentally through a forward thrust or pressure of the handof the operator upon the exterior of the handpiece while engaged in thedrilling operation. My present invention entirely obviates this danger,because the harder the forward pressure upon IOS IIO

the external locking-sleeve 26 the more tightly will the tool be held inthe chuck.

I do not regard the corrugating or notching of the cam-face of thecam-lever as absolutely essential to the carrying out of my invention,sinceitis obvious that owing to the slight pitch orinclination of thecam-face the pin 35 would remain frictionally engaged therewith in anyadjusted position; hut the construction shown is preferred, for thereason that while it does not interfere with the forward sliding of thesleeve for purposes of adjustment it does in a measure tend to check anyexternal rearward movement of the sleeve and consequent loosening of thetool in the chuck while the device is in operation.

I do not limit myself to the exact means shown and described foreffecting the longitudinal interlocking of the two sleeves 26 and 33 norto the exact means disclosed for locking the in'ger 2S in its inner orOperative position, except to the extent that these devices are made thesubject of specific claims, since any other mechanically equivalent andobvious means for effecting the same results might be employed withinthe spirit and purview of my invention.

I claiml. In a dental handpiece, the combination with an outer casingand a spindle mounted to rotate therein, of a tool-holding chuck in theforward end of the spindle, a lever pivotally mounted at its forward endin said spindle longitudinally thereof, said lever having` a short frontface and a relatively long straight inwardly-inclined cam-face extendingfrom its pivotal point to its rear end, longitudinally-slidableconnections intermediate the front face of said lever and the chuck, anexternal longitudinally -slidable sleeve mounted on the casing, an innersleeve slidably mounted upon the spindle within the casing, a lockingdevice intermediate said sleeves which permits a rotary movement only ofthe inner sleeve relatively to the outer sleeve, andaninwardly-extending projection on the inner sleeve which rides upon therearwardly-extending cam-face of the lever and rocks the latter upon theadvance movement of the sleeves, substantially as described.

2. In a dental handpiece, the combination with an outer casing and aspindle mounted to rotate therein, said spindle being longitudinallyslotted througha portion of its length, of a tool-holding chuck in theforward end of the spindle, a lever pivotally mounted at its forward endin the slot of the spindle, said lever having a short front face and arelatively long straight inwardly-inclined corrugated or notchedcam-face disposed at slibstantially a right angle to the front face ofthe lever, longitudinally-slidable connections intermediate the frontface of said lever and the chuck, an external longitudinally-slidablesleeve mounted on the casing, an inner sleeve slidably mounted upon thespindle within the casing, a' locking device intermediate said sleeveswhich permits a rotary movement only of the inner sleeve relatively tothe outer sleeve, and an inwardly-extending pin in said inner sleeve thelower end of which rides upon the notched cam-face ofthe lever and rocksthe latter upon the forward movement of the sleeves, substantially asdescribed.

3. In a dental handpieoe, the combination with an outer casing and aspindle mounted to rotate therein, of a toolholding chuck in the forwardend of the spindle, a cam-lever pivotally mounted in said spindlelongitudinally thereof, longitudinally-slidable connections intermediatethe forward face of said lever and the chuck, an externallongitudinally-slidable sleeve mounted on the casing, an inner sleeveslidably mounted upon the spindle within the casing and within saidouter sleeve, said inner sleeve having an annular groove formed in itsouter surface, a locking-nger pivoted upon said outer sleeve and havinga lug or detent which extends through the casing and into the annulargroove of the inner sleeve, means for locking said finger and its lug inlocking engagement with the inner sleeve, an inwardly-extending pin insaid inner sleeve, the lower end of which impinges upon and rides oveilthe rearwardly-extending face of the cam-lever, actuating the latter ina direction to effect the clamping of the tool by the chuck upon theforward movement of the sleeves, substantially as described.

JOI-IN D. WILKENS.

Witnesses:

SAMUEL N. POND, FREDERICK C. GOODWIN.

IOO

